Chao Li Thomas Su Cheng Lu

Transcription

1 CMPT885 High-Performance Network Final Project Presentation Transport Protocols on IP Multicasting Chao Li Thomas Su Cheng Lu {clij, tmsu, School of Computing Science, Simon Fraser University 4/20/01 1

2 Roadmap Introduction Implementation Details Centralized Approach Scalable Reliable Multicast Tree Based Reliable Multicast Discussion References 4/20/01 2

3 Introduction of Our Project Why we need multicast? Why we need multicast transport protocol? What we will do in our project? 4/20/01 3

4 Introduction of Multicast Unicast Vs Multicast Multiple copy Vs single copy Datalink Layer Support for Multicast Network Layer Support for Multicast Multicast routing Group membership management Group network addressing 4/20/01 4

5 Multicast Transport Protocols Why not just run TCP over Multicast? Multicast Transport Protocols Centralized Approach Unstructured Approach Scalable Reliable Multicast (SRM) Distributed Approach Tree-based Multicast Transport Protocols (TMTP) 4/20/01 5

6 Centralized Multicast Feature Rely on a central site Negative acknowledgment (NACK or NAK) Slotting Advantages Simplicity and ease of implemention Disadvantages 4/20/01 6

7 SRM- Scalable Reliable Multicast Requires only basic IP delivery model Every member is responsible for loss recovery Allow to a wide range of group size 4/20/01 7

8 SRM- Scalable Reliable Multicast Three types of messages Session message Request message Repair message Messages are multicast to the entire group 4/20/01 8

9 SRM- Scalable Reliable Multicast Session messages Report the highest sequence # received by every member Provide information for sender/receivers (status, # of participants, etc.) Estimate host-to-host distance (needed for repair) 4/20/01 9

10 SRM- Scalable Reliable Multicast Request messages loss detected when there is a gap in the sequence # A host wait a random time before multicast the request to the group Any host that has a copy of the requested data can answer 4/20/01 10

11 SRM- Scalable Reliable Multicast Repair messages Wait a random time before multicast the repair packet to the group 4/20/01 11

12 Simulation Environment Topology(from[8][9]) Source Campus Network Campus Network 3Mbit/s Link 1.5Mbit/s Link 4/20/01 12

13 Configuration Details Backgrou nd traffic HTTP Each campus network has one web server, other nodes are clients # of Sessions 800 # of page components 3 TCP/FTP page component size 12KB Senders/receivers spared all over Session interval 10s burst size 80,000 byte The credit goes to Velibor Markovski 4/20/01 13

14 More Configuration Details Multicast traffic CBR traffic (0.04s) 1 sender and 9 receivers 512 packet size Start at 10s for 200sec. Session message frequency 2s(SRM default) More experiment data will be collected on -Larger group size -Star war Trace 4/20/01 14

15 Snapshot(topology) 4/20/01 15

16 Snapshot(router) 4/20/01 16

17 Simulation Results(Request delay) Comparision of Request Delay Centralized Multicast 1.4 SRM Average Request Delay /20/ Receiver Node

18 Simulation Results(Request duplicate) Camparision of Request Duplicate Average Request Duplicate Centralized Multicast SRM /20/01 Receiver Node 18

19 Tree-based Multicast Transport Protocol (TMTP) We are Implementing this protocol in ns2 using C++ and TCl

20 TMTP key features It exploits the IP multicast for packet routing and delivery. It dynamically organize the participants into hierarchical control tree. It achieves scalable reliable multicast via hierarchical control tree used for flow and error control.

21 TMTP hierarchical control tree It organizes the participants into a hierarchical domain. A domain manager(dm) acts as a representative of each domain. Every DM performs two roles for the responsibility for reliability inter-domain and intra-domain.

22 TMTP control tree management The control tree grows and shrinks dynamically in response to additions and deletions to and from the multicast group.

23 TMTP Join Tree A new DM executes an expanding ring search to join the control tree. The JoinTree algorithm Utilizes a time-to-live value (TTL). While (NotDone( NotDone){ Multicast a SEARCH-PARENT msg Collect respondses If (no responses) Increment TTL // try again Else select closet respondent as parent send JOIN-REQ to parent wait for JOIN-CONFIRM reply if (JOIN-CONFIRM received) NotDone = False Else //try again }

24 TMTP Leave Tree A DM only leave the tree after its last local member leaves the group. Internal managers is complicated. Leaf managers is straightforward. If ( I am a leaf manager) send LEAVE-TREE to parent receive LEAVE-CONFIRM terminate Else // I am an internal manager Fullfill all pending obligations send FIND-NEW-PARENT to children receive FIND-NEW-PARENT from all children send LEAVE-TREE to parent

25 TMTP error control(1) An important concept: - limited scope multicast messages It restricts the scope of a multicast message. It sets the TTL value in IP header: multicast radius.

26 TMTP error control(2) TMTP uses 2 error control techniques: sender initiated approach: Periodic positive ACK for receiver, Timeout, Retransmissions (limited scope multicast). receiver initiated approach: Negative ACK (NACK) to sender, NACk is restricted and suppressed, Retransmissions (limited scope multicast).

27 TMTP Flow control Window-based flow control T ack T ack Timer T ack 2 timers: T retrans retrans and T ack T retrans T retrans + T ack T retrans retrans +2 T ack T retrans =n*t ack, n=3 retrans =n*t

28 Test environment (2) We use standard IP multicast; We implement a sender-initiated reliable multicast transport agent using ns2; T ack = RTT, T retrans =3*T ack multicast traffic

29 Performance measure End-to-end delay Packet loss Bandwidth consuming

30 Some comments It is not flexible periodically JoinTree to change hierarchy

31 Reference [1] M. Banikazemi. IP Multicasting: Concepts, Algorithms, and Protocols, IGMP, RPM, CBT, DVMRP, MOSPF, PIM, MBONE, ; charly.kjist.ac..ac.kr/~dwlee/homepage/ipmulitcast.htm [2] B. Williamson. Developing IP Multicasting Networks Volume 1 - Distance Vector Multicast Routing Protocol and Multicast Open Shortest Path First, pp pp , Cisco Press, [3] E. C. Douglas, Internetworking with TCP/IP Volume 1 - Internet Multicasting (IGMP), pp , Prentice-Hall, Inc., [4] S. Deering,, D. Estrin,, D. Farinacci,, V. Jacobson, C. G. Liu, and L. Wei, An Architecture for Wide-Area Multicast Routing, ACM SIGCOMM '94,, vol. 24 no. 4, pp [5] S. Floyd, V. Jacobson, C.-G. Liu, S. McCanne.. and L. Zhang. A Reliable Mulitcast Framework for Light-weight Sessions and Application Level Framing, ACM SIGCOMM 95,, Aug. 1995, pp /20/01 31

32 [6] S. Armstrong, A. Freier,, K. Marzullo, RFC 1301: Multicast Transport Protocol, Feb. 1992, cis.ohio-state. -state.edu/cgi- bin/rfc rfc/rfc1301.html [7] B. Whetten,, G. Taskale. An Overview of Reliable Multicast Transport Protocol II, IEEE Network,, Jan/Feb 2000, pp ; komunikasi.org/.org/pdf/multicast/reliable-multicast-transport- protocol-ii.pdf pdf [8] M. T. Lucas, B. J. Dempsey, and A. C. Weaver. MESH: Distributed Error Recovery for Multimedia Streams in Wide-Area Multicast Networks, In Proceedings of IEEE International Conference on Communication (ICC '97),, pp , June [9] M. T. Lucas. Efficient Data Distribution in Large-Scale Multicast Networks, Ph.D. Dissertation, Department of Computer Science, University of Virginia, May [10] M. Goncalves and K. Niles, IP Multicasting, Concepts and Applications, New York: McGraw-Hill, 1998, pp , pp , pp /20/01 32

33 [11] ns-2 network simulator: isi.edu/nsnam/ns [12] Star Wars trace in ns format: att.com/~.com/~breslau/vint/trace.html [13] C. Hanle and M. Hofmann, Performance Comparison of Reliable Multicast Protocols using the Network Simulator ns- 2, Proceedings of IEEE Conference on Local Computer Networks (LCN),, Boston, MA, USA, October 11-14, [14] V. Markovski, Simulation and Analysis of Loss in IP Networks Simulation scenarios, M. Sci.. Thesis, Department of Engineering Science, Simon Fraser University, Oct. 2000, pp [15] R. Yavatkar,, J. Griffioen,, and M. Suda. A A Reliable Dissemination Protocol for Interactive Collaborative Application, In Proceedings of the ACM Multimedia 95 Conference,, Nov /20/01 33

34 Individual contribution Chao Li: topology construction centralized approach Thomas Su: topology construction SRM background traffic Cheng Lu: building a TMTP agent into ns2 4/20/01 34

35 Thanks 4/20/01 35